login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130049 An inductive sum sequence. 4
0, 3, 6, 7, 17, 12, 32, 20, 51, 29, 72, 39, 97, 50, 127, 63, 161, 77, 197, 92, 236, 108, 279, 126, 327, 145, 378, 166, 432, 188, 489, 211, 550, 235, 614, 260, 681, 286, 751, 313, 826, 341, 906, 371, 989, 402, 1074, 435, 1162, 469, 1252, 504, 1347, 540, 1445, 577 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Complement of A130048. The bisection sequences b(1),b(3),b(5),... and b(2),b(4),b(6),... are strictly increasing, but b(2n)<b(2n-1) for n>=3.

LINKS

Table of n, a(n) for n=1..56.

FORMULA

A130049 is the sequence b defined inductively as follows: Let a(1)=1, a(2)=2, b(1)=0, b(2)=3; for n>=3, let x=Floor(n/2) and y=n-x+1. Then a(n)=least positive integer not among a(1),a(2),...,a(n-1), b(1),b(2),...b(n-1) and b(n)=a(1)+a(2)+...+a(x) if n is even, b(n)=a(y)+a(y+1)+...+a(n) if n is odd.

EXAMPLE

(a(1),a(2),...,a(6))=(1,2,4,5,8,9), so x=4 and b(6)=1+2+4+5=12.

(a(1),a(2),...,a(7))=(1,2,4,5,8,9,10), so y=4 and b(7)=5+8+9+10=32.

CROSSREFS

Cf. A130048, A130050, A130051.

Sequence in context: A227723 A192124 A072773 * A056703 A103831 A217519

Adjacent sequences:  A130046 A130047 A130048 * A130050 A130051 A130052

KEYWORD

nonn

AUTHOR

Clark Kimberling, May 03 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified November 27 16:30 EST 2014. Contains 250240 sequences.